Social determinants of older adult suicide: an ecological study using data of Japanese secondary medical areas

Suicide prevention among older adults is a major public health concern in Japan, where the population is rapidly ageing. In 2020, approximately 40% of all suicide deaths occurred among people aged 60 years and older. Previous suicide prevention efforts have focused primarily on early detection and management of depression, while the social determinants of suicide among older adults remain underexplored. This study examined the associations between social indicators, aggregated lifestyle-related data derived from health checkups, and suicide rates among older adults to inform policy development.

Using publicly available data, we examined the associations between the standardised mortality ratio (SMR) for suicide and socioeconomic factors, lifestyle, and lifestyle-related diseases among adults aged 60 years and older across secondary medical areas, which represent practical administrative units for implementing public health policies. Nonparametric correlation and multiple regression analyses were conducted.

Multiple regression analysis showed positive associations between suicide SMR and hypertension, smoking, daily alcohol consumption, older adult single-person households, and employment rate of older adults among men. The analysis showed negative associations with the number of psychotherapists and psychiatrists and income per taxpayer among women.

Suicide risk among older adults demonstrates distinct gender-specific determinants. Preventive strategies should integrate health-related behaviours, socioeconomic factors, and mental health resource availability, and should be adapted to local contexts to effectively mitigate suicide risk, while acknowledging the limitations inherent in the ecological study design.